The present invention relates to suitcase trucks, and relates more particularly to the base frame assembly of a suitcase truck which is comprised of a base frame equipped with wheels and having two parallel sleeves, two first tubes respectively slidably coupled to the sleeves, two second tubes respectively slidably coupled to the first tubes, two stands fixedly secured to the second tubes, and a transverse connecting bar connected between the stands.
Regular heavy duty suitcase trucks are commonly comprised of a metal frame that is not collapsible. There is also known a suitcase truck having a retractable handle that can be adjusted to the desired height. However, the holding space of the base frame of this structure of suitcase truck is still not adjustable subject to the volume of load carried thereon. Therefore, conventional suitcase trucks tend to overturn when a heavy load is carried thereon.